CD player not responding to open close tray button

Hello all,

I have an Onkyo DX2800 which decided to act up yesterday. The open close button does not work. The symptoms are as follows:

Upon startup, the tray motor is heard to be running. Initially I thought the belt is slipping. I replaced the belt, it did not slip this time, but the tray motor continues to run. The laser eye moves up and down. Nothing happens with or without CD. At this point I shut off the power for fear of burning out the tray motor. On closer inspection, I noticed the tray microswitch does not stop the the tray motor when the switch is activated (tray fully extended, table down; and also when tray is fully inserted, table up). The gears turn the microswitch back to the neutral position, causing the tray motor to run nonstop. I touched the tray motor IC, it is very hot.

The microswitch is the closed type , not the plastic sheath over two ends. I try spraying contact cleaner into it, but no improvement. I did the usual maintenance, oil on spindle bearings, cleaning the lens, lubing the rail, etc. Didn't help.

I then cleaned the door microswitch and replaced a couple of caps (100uf) near the tray motor ICs. Surprisingly, with 3 of the ribbon cables disconnected (2 from laser, 1 from sled motor; the tray motor is connected), the open close buttons works correctly. I connected the 2 laser ribbon cables, and it still works . However , when I connected the sled motor ribbon cables, it is back to the original symptoms (tray motor turns and does not stop, control panel unresponsive). I had initially thought about recapping the Power Supply Unit, as there seem to be some logic error with the startup sequence. However, since it is the spindle and sled motors circuit which keeps tripping the unit up, I tested the sled and spindle motor out of circuit, using a 9v battery. The sled motor works, the spindle did not. Only after turning it a few degrees by hand did it spurt to life and died. That would mean the end of the spindle motor?

I would greatly appreciate any thoughts, thank you very much.
 
The sled motor works, the spindle did not. Only after turning it a few degrees by hand did it spurt to life and died. That would mean the end of the spindle motor?
If the spindle motor does not function (rotate) in a normal way even when powered directly then it most probably needs replacement.

After its replacement I would measure the voltages on the steering and ground lines of the ribbon cables - motors share a common ground (according to the schematic) and you need to know if the tray motor spins because its drive chip is powering it up or because stalled spindle motor is lifting the ground track (voltage wise):

DX-2800_001.jpg
 
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Thank you Madis for your reply.

I am going to confirm if the spindle motor is really dead, but your suggestions did remind me of something "you need to know if the tray motor spins because its drive chip is powering it up or because stalled spindle motor is lifting the ground track (voltage wise)" ...

With the spindle/sled motor connected (P103) only, LA6510 (Q105) , the tray motor driver gets really hot. Then when I connect P104 (tray motor cable), Q105 remains hot, and the tray motor spins incessantly, and at a much higher speed.
 
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Updated : I took out the spindle motor out of the circuit board , leaving the sled motor in. With all four connectors connected, the control panel is responsive. Alas that means the spindle motor is the culprit and after multiple attempts to revive it with 9v DC I am pretty sure it is dead.

A strange behaviour I have noticed though is the lens do not go into focus search, although that may be because the spindle motor is out of the circuit. The home switch works, but the sled did not move backwards once it hit the home switch, as described elsewhere.
 
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Update 2 : I got a working spindle motor and swapped it in. Now the tray work normally open close, but the spindle motor doesn't stop spinning! Is it still a mechanical issue at this point or does this means the electronics around the ICs are whacked?

Thanks for your thoughts.
 
@madis64 do you mind walking me through how to do that? I tried looking at youtube "testing CD player voltages" but didn't come up with anything useful. I would appreciate it very much. I know enough to get a multimeter and switch to the DC mode but that's it:

1. where should I attach ground? anywhere on the chassis or any ground point at P103 or P104?
2. i should attach the other probe to SPD on P103? and probe pin 5 of LA6510 (spindle / tray motor driver)?
3. Should I probe the outputs of the +5v and -5v outputs on the regulators as well? (79L05, 78M05)
4. When checking IC protector QF101 and QF102, I should check for continuity?
What should I be looking for in all the above instances?

I had assumed that the servo circuit operates on the 5V rails, but looking at the LA6510, it mentioned 15V supplies. I did change the 4700uf and 2200uf at the 5V regulators already, but not the 2200ufs at the 15V.

Thank you very much.

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Ok, I managed to figure it out without blowing up stuff. Outputs of pos and neg regs are correct, +5 and -5V. The IC protectors are not open.

Voltages of LA6510 when the tray and spindle motor are connected :
Pin 1: -11
Pin 2: -11
Pin 3 : -11
Pin 4 : 0
Pin 5 : -14
Pin 6 : 2
Pin 7: 2
Pin 8 : 4
Pin 9 : -6
Pin 10 : 14

Voltages of Q104 CXA1082BS
Pin 1 : 5
Pin 43 : 5
Pin 44 :0
Pin 45 : 0
 
Oh, I mean I managed to check the voltages without shorting anything. I haven't been able to reach any conclusion, other than there are outputs from the regulated 5Vs and that the IC protectors are not blown. I appreciate help deciphering the voltages.

I think that the CXA pins 44 and 45 control the spindle motor and there is no voltages at both. On the motor driver itself, pin 3 (spindle negative input?) reads -11? And pin 4 (spindle positive input reads 0, which is expected as it connects directly with CXA pin 45. Where does pin 3 get the -11 from? Hmmm.
 

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Ok, I will try my best:

At around 15V supply, LA6510 can output around 13V. Which, I think, is correct for the spindle motor, if Vout is the difference between V+ and V-. I still can't figure out where the 11V comes from in pin 3 though.

But , in this case, the tray motor Vout would be wrong as difference between V+ and V- should be 0. Unless I missed out a -2V somewhere, in this case 2 - (-2) would give 4V, which would then be correct.

I apologize if my answers are too amateurish as I have no formal training in electronics. I am a biology lecturer by trade. Thank you!
 
I changed the opamp LA6510 and the spindle motor stopped spinning! Putting it back together , the drawer is working properly, the CD load sequence is ok up until spindle spin.

I had to trick the lens as my spindle table is not installed properly yet. When the lens hunted , I put a CD a couple of mm above the lens, and the spindle spin briskly.

Crossing my fingers, once the I install the spindle table, it should be able to play like before.